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Tips

Being Diff-icult

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Polish the O.D. of the output with #600 wet-or-Dry and look for a score mark. If you see one, a sleeve is indicated.
 
Oh yeah, check the bore where the seal goes as well. If you or a previous mechanic managed to gouge it while prying out the seal, you need to repair the damage or it will leak.
 
Now I fear we're scarin' Elliot, Randall.

All is contingent on both good, non-damaged I.D. for the seal O.D. and a proper size I.D. seal with a non-scored surface on the shaft O.D... Some Hylomar on the seal O.D. can sorta fix that issue but if the seal isn't the right I.D. or the surface of the shaft is undercut, a sleeve is a viable "good fix".

The visual inspection will tell the tale.
 
Thanks Randall...Thanks Doc...
Guess I'll just wait to pull, inspect the flange shaft before I make any decisions. It would be nice to do this only once!
 
As long as we're talking about differential leaks....

I spent three hours degreasing my differential yesterday so I can now see the metal under the half inch thick grease. (Diff is off the car). After cleaning, I pulled off the brake drums and the inside of the drums is an oily mess. I don't think this is a brake fluid leak. I'm not planning on rebuilding the entire diff but would like to change any seals, as required, while I have it off and can take to the shop, if necessary. I think I can handle the pinion seal, after reading this thread. Thanks for that.

I understand I can remove the hubs and axles as an assembly, after removing the bolts behind the backing plate/diff flange. I can take that assembly in to the shop and have them replace outer bearings and seals. Are there inner seals that I should be replacing at this time or if I do a competent job on the outer seals, will that keep my brake shoes/drums dry?

Thanks for any tips. Don't have much experience in this area so all comments appreciated!

Photos to follow but Photobucket is not allowed thru my work firewall.

pat
 
Pat-

I'm in a similar situation as I'm cleaning up the differential on my 59. In your case, I think changing out the inner seals in the axle tubes makes sense, since if they are leaking you would get gear oil mixing into the bearings - and in fact that may be why you have the mess you see on the outside. Just my opinion, someone with bettter experience may chime in here.

Randy
 
Randy has it exactly right, there is an inner seal that is leaking and should be replaced. Same deal as the pinion seal, the axle surface where it rides should be in good shape as well (although they are less prone to wear than the pinion).

Personally, I would look for a shop that has the proper tool for separating the hubs. Your local machine shop will likely just stick them in their hydraulic press, which will likely distort the hubs permanently, ruining them. Some people get lucky, but at $300 each for replacement hubs, IMO it's worth doing it right. Or ask the shop if they will pay for new hubs if they ruin your old ones
grin.gif


I'm also allergic to using heat to help them separate. Again, lots of folks do it and claim it's fine ... I've never broken an axle and I don't want to start.

Another alternative, perhaps, is to just replace the inner seal and leave the outer one alone. If the inner seal doesn't leak oil and you don't overgrease the bearings, the outer seal has a lot less work to do. It basically only keeps dirt from working it's way into the wheel bearing grease.

Your Mileage May Vary
 
Thanks for the thoughts on this. What is procedure for replacing inner seal? Is that something I can do at home (OK, assuming I have reasonable mechanical skills...)

pat
 
TR3driver said:
Oh yeah, check the bore where the seal goes as well. If you or a previous mechanic managed to gouge it while prying out the seal, you need to repair the damage or it will leak.
Click to expand...
DrEntropy said:
Now I fear we're scarin' Elliot, Randall.
All is contingent on both good, non-damaged I.D. for the seal O.D. and a proper size I.D. seal with a non-scored surface on the shaft O.D... Some Hylomar on the seal O.D. can sorta fix that issue but if the seal isn't the right I.D. or the surface of the shaft is undercut, a sleeve is a viable "good fix".

The visual inspection will tell the tale.
Click to expand...

Randall- oh Sh*t!! You and doc hit the nail on the head. When I removed the old pinion seal I found a gouge in the bore. Someone had been there before! And doc you are also right "it's scarin me"!!!
OK, can I carefully file the high spots and use a sealer when I put the new seal back in to fill in the low spot? If there is a better method of repairing please let me know.
Also, I have looked high and low for Hylomar and cannot seem to find it--- where can I buy it?
Any help is appreciated... thanks!
 
I say pack paper towel into the bearing tightly (if you dampen it with WD-40 or the like it'll pack tightly) and use either a Dremel with a "barrel" style sanding drum or old-fashioned #220 wet-or-Dry on a radiused stick to reduce the high spots in that O.D... then clean the residue WELL and remove the paper "dam".

Hylomar shows up sporadically... Harbor Freight is rumored to have it, I've found it in a local Auto Zone.
 
Doesn't look too bad; I think if you smooth out the high spots and use some sealer, it should be fine.

But if you want to, you could clean it thoroughly and then work some JB Weld (or similar) epoxy into the gouge. Wait for it to harden(I prefer the stuff that takes overnight, it's a lot stronger than the '5 minute' variety), then file the bore back to shape. Might be a good idea to try to cover the bearing while you do all this, to help keep it clean.

I bought a bunch of Hylomar when Harbor Freight had it cheap, but I don't see it on their web site any more. If you've got a local store, you might check with them to see if there is some left in the storeroom. Otherwise it's a bit hard to find in the US. Moss has it listed (221-556), but it might actually be cheaper and quicker to order it from Peter in the UK:
https://www.ldpart.co.uk/shop/shop.php?c=...e678e57d8db79b1

Of course there are lots of other sealers that work fine too; I'm just partial to the Hylomar because it never hardens. Permatex #3, for example, is a great sealer; I just hate having to chip it away the next time I take something apart.

But I would suggest staying away from the RTV (room temperature vulcanizing) "gasket makers", as they can break off inside the joint and form strings that can cause problems.
 
Thanks doc.... I'm off to harbor freight NOW. Going to buy some small files; afraid I might do more damage with a dremel.
Will look for hylomar... be back later... thanks!
 
"Touch wood" :wink:

In this app, RTV would work fine ~IF~ it is only applied to the seal O.D. and thinly. Putting it on the I.D. of the housing can allow it to be pushed into the 'strings' Randall referred to. Use it if you don't find Hylomar easily. :wink:
 
That's interesting that Permatex is once again touting Hylomar. They brought out a product before called "Hylomar HPF" that I didn't like nearly as well, which was eventually discontinued. The original used a solvent that is frowned on in the USA, maybe trichloroethylene (or was it perc?). According to https://hylomarpl32.com/FAQ.htm they are now using acetone.
 
Blue fingernail polish remover!!! :laugh:

The consistency is thinner in the "new" stuff, too.
 
O ring up against the bearing, layer of heavy grease to hold it in place, dremel tool with a small stone, clean up the raised metal, wipe out the grease, layer of non hardening silicone on the outside of the seal. Chuck the flange in the lathe clean up with 400 and 600 wet/dry, grease liberally and reinstall.

to be honest I don't think the sealant is really necessary because the leak is coming from the seal being distorted by the gouge. There's plenty of sealing surface left behind the gouge once you get the raised portion out of there.

FWIW
 
Just returned from the another auto parts store. Low and behold, they had Hylomar!
Going to take off the high spots on the bore of the diff then use some epoxy to fill before using the Hylomar around the outer edge of the new pinion seal.
Thanks for all the good advice guys!
If I fill it with oil and let it sit on a workbench for a couple of hours, to see if it passes the "leak test" do you think that would be good enough for a "go/no go" before I re-install it?
 
Likely inconclusive.
 
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